Air pump separator method and apparatus

ABSTRACT

A device and method for separating particles by mass is provided in which the particles are entrained in an airstream and are ejected into a collection zone where they will fall under the influence of gravity, but will separate longitudinally by mass with the most massive particles traveling the farthest. As an enhancement to the separation, an apparatus for forming at least one air curtain perpendicular to the ejection direction is provided which causes the falling particles to separate into discrete groups.

This is a continuation of application Ser. No. 935,139filed Nov. 28,1986 which is a continuation of application Ser. No. 748,429, filed June25, 1985 both now abandoned.

BACKGOUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a device and method for separatingsolid materials according to mass by use of an air pump.

2. Description of the Prior Art

Devices and methods for separating materials by using airstreams areknown which usually use the airstream to separate light materials fromheavy materials in that the light materials are carried by the airstreamand the heavy materials are uneffected by or dropped out of theairstream. For example, such devices are shown in U.S. Pat. Nos. 933,532and 4,242,197. The prior art does not disclose devices or methods forseparating materials according to mass by entraining all of thematerials in an airstream at an equal velocity and using the resultingmomentum of the particles to effect the separation. Further, the priorart does not disclose a method or apparatus for entrancing theseparation by such a method incorporating the use of air knives.

SUMMARY OF THE INVENTION

The present invention provides a device and method for separating solidmaterials according to mass by incorporating all of the materials intoan airstream such that all of the particles within the material willhave substantially the same velocity and the ejecting the material froma nozzle whereby the material will fall under influence of gravity atvarious distances from the nozzle depending on the mass of the material.The greater the mass, the farther the material will travel from thenozzle.

Although the material will be separated generally according to its masscan be further utilized by separating various portions of an elongatedpile extending from the nozzle, an additional apparatus and method isprovided in a further embodiment of the invention in which a pluralityof air curtains or air knives are used to separate the airborneparticles into discrete piles. In accordance with this aspect of theinvention, an air curtain is provided perpendicular to the direction ofthe airstream and causes a discrete cut off point at various locationsfor collecting particles within a discrete mass range.

The present invention can be used to separate and classify material andworks especially well when the materials are generally of a similar sizesuch that the materials will in fact be separated according to theirspecific gravity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of an apparatus usable to entrainmaterials into an airstream.

FIG. 2 is a sectional view taken in general along the line II--II ofFIG. 1.

FIG. 3 is a sectional view taken generally along the line III--III ofFIG. 1.

FIG. 4 is a side elevational view of a nozzle and ejection pile.

FIG. 5 is a view taken generally along the line V--V of FIG. 6.

FIG. 6 is a side elevational view of an air curtain separator device.

FIG. 7 is a top elevational view of the device shown in FIG. 6.

FIG. 8 is a sectional view taken generally along the line VIII--VIII ofFIG. 7.

FIG. 9 is a partial sectional view taken generally along the line IX--IXof FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIGS. 1-3 there is shown an air pump generally at 10 which includesan inlet hopper 12 for receiving a supply of dry particulate materialfrom a conveyor or chute 14. The hopper 12 opens at a bottom end into ahorizontal tube 16 which has a material conveyor such as an auger 18therein for moving the particulate material into a pickup chamber 20.The auger 18 is powered by an electrical motor 22 through an appropriategear or pulley arrangement 24, including a pulley 18A coupled to augershaft 18B and a pulley 22A coupled to motor shaft 22B.

As illustrated most clearly in FIGS. 1 and 2, the auger shaft 18b andmotor shaft 22b are aligned in parallel fashion so that the gear orpulley arrangement 24 extends perpendicularly between the two. The auger18 is such that, as illustrated in FIGS. 1 and 3, it extends intoconduit 16, beneath hopper 12 so as to collect material from the bottomend of the hopper to carry the material to the pick-up chamber 20.Accordingly, as illustrated most clearly in FIG. 3, the auger 18 and itsshaft 18b extend beyond both sides of the bottom end of the feederhopper 12 but terminate just prior to the pick-up chamber 20.

An air supply conduit 26 is connected to the pickup chamber 20 and hasan inlet 28 to the chamber 20 directed at an oblique angle to thedirection of the infeed of materials in order to agitate and pick up thematerials into the airstream. As such, the inlet 28 comprises a meansfor mixing the particulate materials within the air stream such that thematerials are entrained in the air stream. The materials picked up inpickup chamber 20 are then carried into mixing chamber 21 where they arefurther entrained in the airstream. Upon exiting the mixing chamber 21,the material laden airstream is accelerated within acceleration chamber23 connected thereto. Because of its tapered construction (an outletdiameter 23a being less than an inlet diameter 23b), the accelerationchamber 23 will cause the entrained materials to travel at a faster andequal velocity. As illustrated, the mixing chamber is formed as astraight cylinder while the acceleration chamber has a conical shapeimparted by tapering of its sidewall 23C. The particulate ladenairstream then exits from the acceleration chamber 23 and passes into anexit or exhaust conduit 30 to be directed to a further discharge point.

An openable collection chamber 32 is provided downstream of the pickupchamber upon a tapered side or wall 23c of acceleration chamber 23 forthe collection of particulate matter which is too heavy for theairstream to carry. The chamber has a hinge 34 on one side and a latch36 on an opposite side to permit the opening and sealing of the chamberas required.

The air pump illustrated is only representative of a number of similardevices which can be utilized in accordance with the present invention.The requirement for the pump is that it be able to entrain theparticulate material into the airstream and to carry the particulatematerial at a predetermined or preselected velocity.

FIG. 4 shows a first embodiment of the invention in which the dischargeconduit 30 has a discharge end 38 supported above ground level 40 by asupport member 42. The particulate material which has been picked up bythe airstream is carried through the discharge conduit 30 at a constantvelocity and all of the particulate material within the airstream hassubstantially the same velocity. The discharge end 38 comprises adischarge means for discharging the particulate laden airstream from theair pump. As the material exits the discharge opening 38, the airstreamdissipates and the material is caused to fall downwardly under theinfluence of gravity. It has been discovered that the material will fallinto an elongated pile 44 in which a first segment 46 will comprise theleast massive (lightest) particulate material and a most distant segment48 will comprise the most massive (heaviest) particulate material andintervening segments 50, 52 will comprise particulate materials havingsuccessively increasing mass. The pile will be a continuous elongatedpile unless the particulate material is substantially equal in size andis comprised of a mixture of particles with widely different specificgravities.

The principle behind the separation in this method is that a momentum isimparted to the particulate material, momentum being the product of massand velocity. Since all of the particulate material has the samevelocity, the material having a higher mass will have a higher momentumand thus will travel farther from the discharge outlet 38 as describedabove.

This method can be used to separate and classify materials according totheir mass and further can be used to separate and classify materialsaccording to their specific gravity particularly where the size of theparticles are substantially equal. Thus, materials of a particularspecific gravity will fall a particular distance from the outlet openingand thus can be easily identified and separated. If the particulatematerials are within a small range of sizes, they can also be separatedby using the disclosed method although there may be some overlap betweensuccessive areas.

To enhance the separation of materials, a further embodiment of thepresent invention is illustrated in FIGS. 5-9. In this embodiment, anair curtain or air knife separator device 54 is utilized to providediscrete collection zones for the particulate material. The air knifeseparator 54 is independent from the discharge conduit but it is placedclosely adjacent the discharge opening 38.

The air knife device 54 is comprised of an elongated box-like framewhich is open at at least a first end 58 to receive the stream ofparticulate material.

To supply the air knife or air curtain function, a blower 60 isconnected to an air conduit manifold 62 that extends longitudinallyalong a closed top wall 63 of the frame. A plurality of conduits 64 tapinto the manifold and extend laterally across the top wall 63 and extenddownwardly along opposite enclosed side walls 68, 70 a portion of theheight of the frame. The side walls 68, 70 are closed at a top portionto prevent interference with or disturbance of the particulate laden airstream as it passes through the separator device. The side walls 68, 70are open at a bottom portion to permit air to escape from the enclosureas it dissipates.

As the side conduits 64 extend downwardly along the sides 68, 70 of theseparator device, a plurality of tubes 72 tap into the lines 64 andextend through the side walls 68, 70 at open ends 73. Thus, jets of airindicated by arrows 74 in FIGS. 8 and 9 form an air curtain at selectedlongitudinal positions along the length of the separator device 54. Asillustrated, the jets of air 74 are directed horizontally, and becauseof the linear vertical arrangement of same, the air curtains formed bythe air jets are vertically oriented. This air curtain forms a barrierperpendicular to the direction of the particulate laden air stream whichcan be penetrated only by particles having a momentum of somepredetermined amount or greater. Thus, all particles having a momentumless than the selected value are stopped by the air curtain and fallinto a collection bin 76 for further use.

The airborne particulate matter passing through the first air curtainthen proceeds toward the next air curtain, the momentum of all particlesdecreasing due to decreasing velocity with the additional distance.Again, the particles having smaller momentum are separated from thosehaving a higher momentum and a second discrete pile can be collected.

The number and placement of the air curtains can be selectivelydetermined based on the mix of materials being separated and theparticular mass of the materials as well as the airstream velocity.

As seen in FIG. 6, the particulate matter falls into distinct piles dueto the action of the air knives as opposed to a single elongated pile asseen in FIG. 4. Thus, the separation and classification of the materialscan proceed more accurately by use of the air knives.

The method and apparatus of this invention finds particular use inseparating heterogeneous materials such as sand mixed with smallmetallic particles and small organic and inorganic materials such aswould be obtained in a final screen separator step as disclosed in myU.S. Pat. application No. 4,648,650 patent application entitled "SCREENSEPARATOR METHOD FOR FOUNDRY WASTE MATERIALS". By the use of the presentinvention additional recyclable materials can be separated and reclaimedfrom the "waste sand" output disclosed in that application whichcomprises a heterogeneous mixture of particles less than 1/4 to 1/8inches in diameter.

The usefulness of the present invention is by no means limited to suchuse in that it can be used to separate or classify a wide array ofmaterials by size if homogeneous or by weight if heterogeneous and ofequal size, but always by mass regardless of size or homogeneity.

As is apparent from the foregoing specification, the invention issusceptible of being embodied with various alterations and modificationswhich may differ particularly from those that have been described in thepreceeding specification and description. It should be understood thatwe wish to embody within the scope of the patent warranted hereon allsuch modifications as reasonably and properly come within the scope ofour contribution to the art.

We claim as my invention:
 1. A method of separating particulate matterby mass comprising the following steps:conveying a supply of saidparticulate matter into a feeder hopper; feeding said particulate matterin said feeder hopper into a first conduit containing an auger, saidauger having a shaft; driving said auger with a motor having a shaftextending parallel to the shaft of said auger, the auger being driven bya belt extending between a first pulley located on the motor shaft and asecond pulley located on the auger shaft; supplying an air stream at aninlet located at a discharge end of said auger relative to the conduit,which inlet lies in a horizontal plane; picking up particulate matter insaid airstream; mixing said particulate matter with said airstreamwithin a straight cylinder mixing chamber communicating with adownstream end of said conduit so as to entrain said matter within saidairstream; accelerating said material laden airstream within a conicalacceleration chamber communicating with a downstream end of said mixingchamber so as to increase and equalize velocities of individual piecesof particulate matter; collecting particulate matter within saidacceleration chamber which does not become entrained in said airstreamfrom a side of said acceleration chamber; discharging said particulateladen airstream along a horizontal path from an open end of a secondconduit communicating with a discharge end of said acceleration chamberinto a collection zone; forming at least one air curtain by injectingair from a plurality of vertically aligned, horizontally directed airjets; separating the particulate matter downstream from the open end ofthe second conduit into discrete portions by positioning at least oneair curtain perpendicular to the discharge direction at selectedlocations along the discharge flow path; and collecting discreteportions of the particulate matter from the collection zone for furtherutilization;whereby said particulate matter will be separated in saidcollection zone with the more massive particulate matter travelingfurther from the open end of said conduit than the less massiveparticulate matter.
 2. An apparatus for separating particulate matter bymass comprising:a feeder hopper for feeding a supply of particulatematter, said feeder hopper having an inlet end and a discharge end; anauger located in a conduit beneath said feeder hopper, said conduithaving a top opening communicating with said discharge end of saidfeeder hopper, said auger having two ends each of which extends beyondsaid discharge end of said feeder hopper; a drive system for drivingsaid auger comprising a motor having a shaft extending parallel to ashaft of said auger, a pulley located on each of said shafts, and adrive belt extending between said pulleys; an airstream inletcommunicating with said conduit and located at a discharge end of saidauger, said auger and auger shaft terminating prior to said airstreaminlet; an airstream flowing into said conduit through said airstreaminlet for picking up particulate matter within said airstream; astraight cylinder-shaped mixing chamber coupled to the discharge end ofsaid auger within which said particulate matter is mixed within saidairstream so as to entrain said particulate matter within saidairstream; and a conically-shaped conduit acceleration chamber coupledto an outlet of said mixing chamber within which said particulate ladenairstream is accelerated; a collection bin located on a tapered wall ofsaid conically-shaped conduit and in communication with the interiorthereof for capturing particulate matter not entrained in saidairstream; a conduit coupled to an outlet of said acceleration chamberand having a discharge end; a collection zone for collecting particulatematter dropping out of said airstream upon exiting of said airstreamfrom the discharge end of said conduit; and at least one air curtainformed by a plurality of vertically aligned, horizontally directed airjets, said air curtain positioned perpendicularly to the discharge pathof the particulate laden air stream.
 3. An apparatus for separatingparticulate matter by mass comprising:means for delivering a supply ofparticulate matter to a horizontal cylindrical conduit, an auger feederlocated within said conduit for conveying said particulate matter into apick-up chamber, said auger feeder having two ends, each of whichextends beyond a discharge outlet of said means for delivering a supplyof particulate matter; means for driving said auger comprising a motorhaving a shaft positioned parallel to a shaft of said auger, a firstpulley located on an end of said motor shaft, a second pulley located onan end of said auger, and a drive belt extending between said first andsecond pulleys; means for supplying an airstream through an inlet at anangle relative to said pick-up chamber, which inlet lies in a horizontalplane and is located at a discharge end of said auger feeder, said augerand auger shaft terminating prior to said inlet; means for causing saidairstream to pick up particulate matter discharged from said augerfeeder; means located downstream of said auger feeder comprising astraight cylinder for mixing said picked-up particulate matter withinsaid airstream so as to entrain a major portion of said particulatematter within said air stream; means for accelerating said particulateladen airstream comprising a conically-shaped conduit located downstreamof said means for mixing; means for collecting and removing particulatematter from said conically-shaped conduit which is not entrained in saidairstream located on a tapered wall of said conically-shaped conduit;means for horizontally discharging said particulate laden airstream fromsaid conically-shaped conduit into a collection zone; and means forcollecting discrete portions of said particulate matter from saidcollection zone for further utilization comprising air curtains formedby vertically aligned, horizonally directed air jets positioned atselected locations along the discharge flow path perpendicular to thedischarge direction;whereby, said discharge particulate matter isseparated into discrete areas of more massive particulate matter andareas of less massive particulate matter as they fall into thecollection zone under the influence of gravity.
 4. An apparatusaccording to claim 3 wherein said means for accelerating saidparticulate laden airstream comprises a chamber having tapered sides andsaid collecting and removing means comprises an openable collectionchamber located on a tapered side of said acceleration chamber.
 5. Anapparatus for separating particulate matter by mass comprising:a feederhopper for receiving a supply of particulate matter, said feeder hopperhaving an inlet and a discharge end with two sides; a conduit orientedhorizontally and having a top opening communicating with said dischargeend of said feeder hopper; an auger and a shaft thereof located in asectional portion of said conduit for conveying particulate matter fromsaid hopper and discharging the particulate matter into a pickup portionof said conduit at an end of said auger, said auger extending beyondboth sides of the discharge end of said feeder hopper, said auger andauger shaft terminating prior to said pickup portion; a motor having ashaft extending therefrom with a first pulley located thereon; a beltdrive extending from said first pulley to a second pulley located on theauger shaft; an airstream supplied through an inlet at an angle relativeto the conduit, which inlet lies in a horizontal plane and which islocated at a discharge end of said auger; a pickup chamber located atsaid discharge end of said auger and communicating therewith in whichsaid airstream picks up particulate matter discharged by said auger; astraight cylinder-shaped mixing chamber located at a downstream side ofsaid pickup chamber and communicating therewith in which saidparticulate matter is mixed with said airstream so as to entrainparticulate matter in said airstream, all of said airstream beingdirected into said mixing chamber; a conically-shaped accelerationchamber located downstream of said mixing chamber and communicatingtherewith in which said particulate laden airstream is subject to anincrease in velocity; a collection chamber located on a conical wall ofsaid acceleration chamber and communicating with said accelerationchamber to collect particulate matter not entrained in said airstream; adischarge conduit located downstream of said acceleration chamber andcommunicating therewith from which said particulate laden air stream isdischarged; a collection zone; and at least one air curtain formed insaid collection zone perpendicular to the discharge flow path of saidmaterial laden airstream by a plurality of vertically aligned,horizontally directed air jets;whereby, said airstream carries saidentrained particulate matter out of an open end of said conduit intosaid collection zone such that the particulate matter travels in ahorizontal path through each air curtain formed by said horizontallyaligned air jets so that the more massive particulate matter is carriedfurther than the less massive particulate matter with said air curtainsegregating said particulate matter into discrete portions.
 6. Anapparatus according to claim 5 wherein said means for forming an aircurtain comprises:a box-like frame member with an open end for receivingsaid particulate laden air stream; an air blower; an air manifoldconnected to said blower; and a plurality of air conduits connected tosaid manifold having openings directed towards the interior of saidframe member perpendicular to the discharge direction of said airstream.
 7. An apparatus according to claim 5, including a plurality ofcontainer means for receiving said separated particulate matter in saidcollection zone.